Framework for provisioning network services in cloud computing environment

ABSTRACT

This disclosure relates generally to provisioning network services in a cloud computing environment, and more particularly to framework for provisioning network services in a heterogeneous cloud computing environment. In one embodiment, the disclosure includes a network as a service (NaaS) layer under a cloud provisioning platform. The NaaS layer can be interfaced with any cloud provisioning platform. The NaaS layer serves the networking needs of the heterogeneous cloud environment. It provides network services like monitoring, notifications, QoS policies, network topology and other services. For example, the cloud provisioning platform defines a virtual network and attaches a plurality of virtual machines to it. All the communications related to creation/deletion/update of virtual networks, virtual subnets, virtual ports, virtual router, virtual interfaces etc., are sent to the NaaS layer. On receiving the communication, the NaaS layer takes necessary steps to provide the network services as per the needs of the request. Apart from provisioning, the NaaS layer periodically monitors the network elements as well.

PRIORITY CLAIM

This U.S. patent application claims priority under 35 U.S.C. § 119 to:India Provisional Application No. 3327/MUM/2015, filed on Aug. 31, 2015.The entire contents of the aforementioned application are incorporatedherein by reference

TECHNICAL FIELD

This disclosure relates generally to provisioning network services in acloud computing environment, and more particularly, to framework forprovisioning network services in a heterogeneous cloud computingenvironment.

BACKGROUND

Cloud computing is an Internet-based computing that provides sharedprocessing of resources and data to computers and other devices based ondemand. The cloud computing provides access to the resources likenetworks, servers, storage, applications and services. These resourcescan be rapidly provisioned and released with minimal management effortin the cloud computing. The cloud infrastructure that can be utilized ina pay-by-use method by public is called as a Public cloud. The cloudinfrastructure that is utilized by a single organization internally andwhich is not available for public is called as a Private cloud.

The inventors here have recognized several technical problems with suchconventional systems, as explained below. The services provided in cloudcomputing includes Software as a Service (SaaS), Platform as a Service(PaaS) and Infrastructure as a Service (IaaS). The IaaS, offers Computeas a Service for deployment of Virtual Machines (VMs), Storage as aService for providing storage space to the VMs and Network as a Servicefor providing connectivity with services such as layer 2 switching,layer 3 routing, load balancing, firewall etc., to the VMs by using poolof infrastructure resources (CPU cores, memory, hard disk space, networkswitch, router, etc.) available in the cloud. The Network as a Servicemakes use of the underlying physical networks for provisioning servicesto the VMs. Examples of the physical networks include a Software DefinedNetwork (SDN) type, a non-SDN type (also called as a legacy network) ora hybrid of both (heterogeneous network). Moreover, in cloud computing,resources are hosted at public and private clouds and a simple one touchprovisioning becomes a key requirement for the customers. Such networkprovisioning requires appropriate interfaces and information exchangewith the public and private cloud resources. The optimal utilization ofthe resources that are geographically distributed across differentlocations (private cloud resources) and the public cloud resourcesaccessible via the Internet is a challenging task.

SUMMARY

Embodiments of the present disclosure present technological improvementsas solutions to one or more of the above-mentioned technical problemsrecognized by the inventors in conventional systems. For example, in oneembodiment, a method for provisioning network services in aheterogeneous cloud computing environment is provided. The methodincludes assigning compute and storage resources to one or more virtualmachine provisioning requests and generating one or more network servicerequests for at least one of creation, update or deletion of at leastone of virtual networks, subnets, ports, routers and interfaces by thecloud provisioning platform. Further, one or more network servicerequests are sent to a middle layer called network as a service (NaaS)layer by the cloud provisioning platform for provisioning networkservices, wherein the NaaS layer comprises a plurality of interfacesincluding a north bound interface module, a south bound interfacemodule, a network orchestration and intelligence module and an east westinterface module for provisioning network services in a cloud system.Subsequently, underlying physical networks are configured for each ofthe network service requests.

In another embodiment, a system for provisioning network services in aheterogeneous cloud computing environment is disclosed. The systemincludes at least one processor, and a memory communicatively coupled tothe at least one processor, wherein a memory includes a network as aservice (NaaS) layer module for provisioning network services in aheterogeneous cloud computing environment. The system includes assigningcompute and storage resources to one or more virtual machineprovisioning requests and generating one or more network servicerequests for at least one of creation, update or deletion of at leastone of virtual networks, subnets, ports, routers and interfaces by thecloud provisioning platform. Further, one or more network servicerequests are sent to a middle layer called Network as a Service (NaaS)layer by the cloud provisioning platform for provisioning networkservices, wherein the NaaS layer comprises a plurality of interfacesincluding a north bound interface module, a south bound interfacemodule, a network orchestration and intelligence engine and an east westinterface module for provisioning network services in a cloud system.Subsequently, underlying physical networks are configured for each ofthe network service requests sending one or more network servicerequests to the NaaS layer by the cloud provisioning platform whereinthe NaaS layer comprises a plurality of interfaces including a northbound interface module, a south bound interface module and an east westinterface module for provisioning network services in a cloud system andappropriately configuring the underlying physical network for each ofthe network service requests.

In yet another embodiment, a non-transitory computer readable mediumembodying a program executable in a computing device for provisioningnetwork services in a heterogeneous cloud computing environment isdisclosed. The program comprises a program code for a network as aservice (NaaS) layer module for provisioning network services in aheterogeneous cloud computing environment. The program code includesassigning compute and storage resources to one or more virtual machineprovisioning requests and generating one or more network servicerequests for at least one of creation, update or deletion of at leastone of virtual networks, subnets, ports, routers and interfaces by thecloud provisioning platform. Further, one or more network servicerequests are sent to a middle layer called network as a service (NaaS)layer by the cloud provisioning platform for provisioning networkservices, wherein the NaaS layer comprises a plurality of interfacesincluding a north bound interface module, a south bound interfacemodule, a network orchestration and intelligence module and an east westinterface module for provisioning network services in a cloud system.Subsequently, underlying physical networks are configured for each ofthe network service requests.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory onlyand are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this disclosure, illustrate exemplary embodiments and, togetherwith the description, serve to explain the disclosed principles.

FIG. 1 illustrates an exemplary system for provisioning network servicesin a heterogeneous cloud computing environment, according to someembodiments of the present disclosure.

FIG. 2 illustrates a framework for provisioning network services in acloud computing environment in accordance with some embodiments of thepresent disclosure.

FIG. 3 illustrates a network as a service layer that provisionsnetworking needs of a heterogeneous cloud computing environment inaccordance with some embodiments of the present disclosure.

FIG. 4 illustrates the evaluation process involved in the networkingprovisioning with respect to the Open Stack Icehouse cloud software inaccordance with some embodiments of the present disclosure.

FIG. 5 is a flow chart depicting a method for provisioning networkservices in a heterogeneous cloud environment accordance with someembodiments of the present disclosure.

DETAILED DESCRIPTION

Exemplary embodiments are described with reference to the accompanyingdrawings. In the figures, the left-most digit(s) of a reference numberidentifies the figure in which the reference number first appears.Wherever convenient, the same reference numbers are used throughout thedrawings to refer to the same or like parts. While examples and featuresof disclosed principles are described herein, modifications,adaptations, and other implementations are possible without departingfrom the spirit and scope of the disclosed embodiments. It is intendedthat the following detailed description be considered as exemplary only,with the true scope and spirit being indicated by the following claims.

System and method for provisioning network services in a heterogeneouscloud computing environment is disclosed. The system can be implementedin a variety of computing devices. The computing devices that canimplement the described system include, but are not limited to, desktopcomputers, laptops or other portable computers, multiprocessor systems,microprocessor based programmable consumer electronics, laptops, networkcomputers, minicomputers, mainframe computers, and the like. Althoughthe description herein is with reference to certain computing systems,the system may be implemented in other devices, albeit with a fewvariations, as will be understood by a person skilled in the art.

In the present disclosure, system and method for provisioning networkorchestration and network services in the heterogeneous cloud computingenvironment is disclosed. The framework includes a middle layer that canbe interfaced with any cloud provisioning platform. The proposedframework includes a network as a service (hereinafter called as NaaS)layer as a middle layer with modules for a northbound, a core module, aneast-west and a south bound interfacing.

The manner in which the described system is implemented to enableconcurrent principal component analysis computation has been explainedin detail with respect to the following figure(s). While aspects of thedescribed system can be implemented in any number of different computingsystems, transmission environments, and/or configurations, theembodiments are described in the context of the following exemplarysystem.

FIG. 1 schematically illustrates a system 100 for provisioning networkservices in a heterogeneous cloud computing environment, according to anembodiment of the present disclosure. As shown in FIG. 1, the system 100includes one or more processor(s) 102 and a memory 104 communicativelycoupled to each other. The memory 104 includes a network as a service(NaaS) layer module 106 that provisions network services requested by amultiple clients in a heterogeneous environment. The system 100 alsoincludes interface(s) 108. Although FIG. 1 shows example components ofthe system 100, in other implementations, the system 100 may containfewer components, additional components, different components, ordifferently arranged components than depicted in FIG. 1.

The processor(s) 102 and the memory 104 may be communicatively coupledby a system bus. The processor(s) 102 may include circuitryimplementing, among others, audio and logic functions associated withthe communication. The processor 102 may include, among other things, aclock, an arithmetic logic unit (ALU) and logic gates configured tosupport operation of the processor(s) 102. The processor(s) 102 can be asingle processing unit or a number of units, all of which includemultiple computing units. The processor(s) 102 may be implemented as oneor more microprocessors, microcomputers, microcontrollers, digitalsignal processors, central processing units, state machines, logiccircuitries, and/or any devices that manipulate signals based onoperational instructions. Among other capabilities, the processor(s) 102is configured to fetch and execute computer-readable instructions anddata stored in the memory 104.

The functions of the various elements shown in the figure, including anyfunctional blocks labeled as “processor(s)”, may be provided through theuse of dedicated hardware as well as hardware capable of executingsoftware in association with appropriate software. When provided by aprocessor, the functions may be provided by a single dedicatedprocessor, by a single shared processor, or by a plurality of individualprocessors, some of which may be shared. Moreover, explicit use of theterm “processor” should not be construed to refer exclusively tohardware capable of executing software, and may implicitly include,without limitation, digital signal processor (DSP) hardware, networkprocessor, application specific integrated circuit (ASIC), fieldprogrammable gate array (FPGA), read only memory (ROM) for storingsoftware, random access memory (RAM), and non-volatile storage. Otherhardware, conventional, and/or custom, may also be included.

The interface(s) 108 may include a variety of software and hardwareinterfaces, for example, interfaces for peripheral device(s), such as akeyboard, a mouse, an external memory, and a printer. The interface(s)108 can facilitate multiple communications within a wide variety ofnetworks and protocol types, including wired networks, for example,local area network (LAN), cable, etc., and wireless networks, such asWireless LAN (WLAN), cellular, or satellite. For the purpose, theinterface(s) 108 may include one or more ports for connecting the system100 to other network devices.

The memory 104 may include any computer-readable medium known in the artincluding, for example, volatile memory, such as static random accessmemory (SRAM) and dynamic random access memory (DRAM), and/ornon-volatile memory, such as read only memory (ROM), erasableprogrammable ROM, flash memories, hard disks, optical disks, andmagnetic tapes. The memory 104, may store any number of pieces ofinformation, and data, used by the system 100 to evaluate thequalitative and quantitative performance rating. The memory 104 may beconfigured to store information, data, applications, instructions or thelike for system 100 to carry out various functions in accordance withvarious example embodiments. Additionally or alternatively, the memory104 may be configured to store instructions which when executed by theprocessor 102 causes the system 100 to behave in a manner as describedin various embodiments. The memory 104 includes the NaaS layer 106 andother modules. The module 106 include routines, programs, objects,components, data structures, etc., which perform particular tasks orimplement particular abstract data types.

In the present disclosure, an open source platform called OpenNaaS (OpenPlatform for network as a service) is used for developing the prototypefor the network as a service layer (i.e., NaaS layer 106). Also in theproposed framework, only the basic java services are used and is notdependent on any of the components present in OpenNaaS. Therefore, theNaaS layer 106 can be easily interfaced with any cloud provisioningsystem by means of suitable interfaces. In an example, the proposeddisclosure used an Open Stack interface. For example, the network as aservice layer supports modularization in java with extensive librarysupport. It is easy to develop and deploy applications or services onthe NaaS layer 106. In addition, a Software Defined Network (SDN)control plane management is also incorporated in this layer along withmodules in controllers like a Floodlight and an OpenDayLight SDNcontrollers.

FIG. 2 depicts a framework 200 for provisioning network services in aheterogeneous cloud computing environment. The framework 200 of a cloudsystem includes a plurality of tenants (consumers of the resources), acloud orchestrator 202, a cloud provisioning platform (For e.g., OpenStack) 204 and a cloud administrator. The cloud orchestrator 202 acts asan interface with different public and private clouds to provide cloudprovisioning services. The cloud provisioning platform 204 includes acloud controller, a management and a plurality of service entities alongwith a pool of resources. The management entities reside in the cloudcontroller and the service entities are directly a part of the resourcesor a middle layer (network as a service layer 206) controlling theunderlying resources.

The cloud orchestrator 202 distributes the virtual machine provisioningrequests received by tenants or a cloud administrator to cloudprovisioning platform 204. The cloud provisioning platform 204 interfacedefines a virtual network and requests attachment of virtual machines toone or more virtual network through virtual machine provisioningrequests. All the communication related to creation or deletion orupdate of a virtual network, a virtual subnet, a virtual port etc., aresent to the NaaS layer 106 through corresponding HTTP methods (POST,PUT, GET and DELETE). On receiving the communication, the NaaS layer 106takes necessary steps to provide the network services. The virtualnetworks provisioned can be an overlay or an underlay network and theseare associated with the underlying physical network through appropriateconfigurations.

The overlay network is a tunneling kind of network created between twoendpoints and operates on top of the underlying physical network. Theoverlay network assumes the physical network as an always availableresource. Generic Routing Encapsulation (GRE) and Virtual eXtensibleLocal Area Network (VXLAN) tunnels are few examples of the overlaynetwork. In an example embodiment, the NaaS layer 106 provisions tunnelsbetween appropriate end points to enable communication between thevirtual machines.

The underlay network is a physical network which needs configuration ofthe actual network elements such as switches, routers, firewalls, etc.VLAN is an example of an underlay network. The network elements in theunderlay network can be either SDN enabled or pure legacy in nature. Theproposed framework configures the network elements appropriately toenable communication. The legacy control/Network Management Systems(NMS) are employed for performing configurations on the non-SDN networkelements. Whereas, in case of SDN, the proposed framework configuresappropriate rules inside the corresponding network elements through theSDN controllers 208. Similarly, this proposed framework configures thenetwork resources to provide routing, firewall, load balancing, DynamicHost Configuration Protocol (DHCP) and other services. This can deploySDN controllers 208 and provide NFV services through a set of dedicatedresources. This is also responsible to provide access to the Internetand other geographically distributed resources through the dedicatedexternal networks.

The NaaS layer 106 that is described in detail in FIG. 3 is underneaththe cloud provisioning system (i.e., a private cloud) and one instanceis required for each deployment of the private cloud. The networkservices are provided to a GUI (Graphical User Interface) and other userapplications by the NaaS layer 106. The proposed NaaS layer 106 usesseparate east west bound interfaces to manage the resources in thepublic cloud and communicate with different instances of NaaS 106deployed in different private clouds. A distributed approach is followedfor network orchestration and services provisioning in coordination withthe top level cloud orchestrator entity. The data exchange mechanism isdesigned and implemented for the NaaS layer 106.

FIG. 3 illustrates a network as a service layer 106 that provisionsnetworking needs of a heterogeneous cloud computing environment,according to an embodiment of the present subject matter. Moreparticularly, FIG. 3 depicts the detailed components of the NaaS layer106. On the north bound side, the NaaS layer has North Bound API's(Application Programming Interface) 302 and cloud interfacing module304. The North Bound API'S 302 provide different services to therequests received from a Graphical User Interface (GUI) and other userapplications. The cloud interfacing module 304 interfaces with differentclouds to provide network service requests that are received by the NaaSlayer 106. While on the south bound side, it has the SDN interfacemodules 306 and non-SDN (legacy) interface modules 308 that communicatewith the corresponding network control/management systems. The SDNinterface module communicates with the SDN controllers 208 (Floodlight,OpenDayLight, etc.) and Non-SDN controllers 210 (as shown in FIG. 2).Also, an optimization engine and information exchange modules aredeveloped in SDN controllers 208 to support dynamic scalability in SDN.The NaaS layer 106, also comprises of east west interface module 312 forexchanging data among different instances of network as a service layer106 deployed for different private clouds. Moreover, the east westinterface module 312 may be used to provide communication with othernetwork as a service platforms or public cloud entities.

In between the north bound and south bound interfaces, the NaaS layer106 includes a core engine called as a network intelligence andorchestration module 310. The network intelligence and orchestrationmodule 310 includes a topology module, a network elements monitoringmodule, a policy management module, a dynamic QoS provisioning moduleetc.

Apart from provisioning, the NaaS layer 106 also periodically monitorsthe networks. For example, a topology module shown in the NaaS layer 106keeps track of the switches, inter-switch links, and switch to hostconnections. This solution makes use of the SDN interface module 306 andthe non-SDN interface module 308 for collecting the topology relatedinformation. The NaaS layer 106 also maps a local to global topologywith respect to the distribution of cloud resources. Further, the NaaSlayer 106 collects required network statistics for network healthmonitoring and dynamic QoS provisioning. The NaaS layer 106 can allow ordeny network provisioning requests or divert them to different resourcepools as per the network health.

Further, the NaaS layer 106 supports easy deployment of a multiple RESTAPIs for providing different services to application developers. Forinstance, the GUI of the NaaS layer 106 makes use of the REST APIsexposed to provide several control and policy features to the users. Thequality of service (QoS) policy package including features such as ratelimiting, egress traffic shaping, egress traffic scheduling, dynamic QoSassignment, quota based limits, dynamic SDN control plane managementetc., are supported by the above mentioned APIs. The cloudadministrators can utilize these features to suit the businessrequirements and also to prioritize the services to different tenants.

In an example embodiment, evaluation of the cloud network servicesprovisioning using the NaaS layer 106 in Open Stack Icehouse cloudprovisioning setup is disclosed. A lab environment consisting ofworkstations for deploying the Open Stack 3-node architecture thatcomprises of a controller node, network node and compute nodes isdisclosed.

FIG. 4 is an example of the evaluation process involved in the networkprovisioning system with respect to the Open Stack Icehouse cloudsoftware. The Controller Node 402, the SDN controller 208 and theNon-SDN controller 210 are connected to the NaaS layer 106 to providenetwork services to Open Stack Cloud.

FIG. 5 illustrates a flow chart depicting a method for provisioningnetwork services in a heterogeneous cloud environment. At block 502, oneor more virtual machine provisioning requests are received from thecloud orchestrator 202 and flow down to the cloud provisioning platform204. Further at block 504, the required compute and storage resourcesare assigned by the cloud provisioning platform to the virtual machineprovisioning requests and further the one or more network servicerequests are generated. At block 506, the one or more network servicerequests are sent to the NaaS layer 106 by the cloud provisioningplatform 204 for providing network services. Appropriate configurationof the physical network elements to enable communication between thevirtual machines is performed by the NaaS layer 106 via thecorresponding SDN controllers 208 or Non-SDN controllers 210 (asmentioned in FIG. 2) at block 508. Furthermore at block 510, networkservices such as network health monitoring, virtual machine networkinformation subscriptions, notifications for registered subscriptions,network topology, dynamic QoS provisioning, load balancing provisioning,firewall provisioning, dynamic SDN scalability, NFV based provisioningwith service chaining etc., are provided by NaaS layer 106 for thevirtual machines and virtual networks provisioned in the cloudprovisioning platform 204 via cloud orchestrator 202 (as mentioned inFIG. 2).

The illustrated steps are set out to explain the exemplary embodimentsshown, and it should be anticipated that ongoing technologicaldevelopment will change the manner in which particular functions areperformed. These examples are presented herein for purposes ofillustration, and not limitation. Further, the boundaries of thefunctional building blocks have been arbitrarily defined herein for theconvenience of the description. Alternative boundaries can be defined solong as the specified functions and relationships thereof areappropriately performed. Alternatives (including equivalents,extensions, variations, deviations, etc., of those described herein)will be apparent to persons skilled in the relevant art(s) based on theteachings contained herein. Such alternatives fall within the scope andspirit of the disclosed embodiments. Also, the words “comprising,”“having,” “containing,” and “including,” and other similar forms areintended to be equivalent in meaning and be open ended in that an itemor items following any one of these words is not meant to be anexhaustive listing of such item or items, or meant to be limited to onlythe listed item or items. It must also be noted that as used herein andin the appended claims, the singular forms “a,” “an,” and “the” includeplural references unless the context clearly dictates otherwise.

Furthermore, one or more computer-readable storage media may be utilizedin implementing embodiments consistent with the present disclosure. Acomputer-readable storage medium refers to any type of physical memoryon which information or data readable by a processor may be stored.Thus, a computer-readable storage medium may store instructions forexecution by one or more processors, including instructions for causingthe processor(s) to perform steps or stages consistent with theembodiments described herein. The term “computer-readable medium” shouldbe understood to include tangible items and exclude carrier ayes andtransient signals, i.e., be non-transitory. Examples include randomaccess memory (RAM), read-only memory (ROM), volatile memory,nonvolatile memory, hard drives, CD ROMs, DVDs, flash drives, disks, andany other known physical storage media.

It is intended that the disclosure and examples be considered asexemplary only, with a true scope and spirit of disclosed embodimentsbeing indicated by the following claims.

What is claimed is:
 1. A processor-implemented method for provisioningnetwork services in a heterogeneous cloud computing environment,comprising: receiving, by a cloud provisioning platform, one or morevirtual machine provisioning requests from a plurality of cloudadministrators, wherein one or more virtual machine provisioningrequests are distributed to said cloud provisioning platform via a cloudorchestrator; assigning of compute and storage resources to one or morevirtual machine provisioning requests and generating one or more networkservice requests for at least one of creation, update, and deletion ofat least one of virtual networks, subnets, ports, routers and interfacesby the cloud provisioning platform; sending the one or more networkservice requests to a Network as a Service (NaaS) layer by the cloudprovisioning platform for provisioning the network services; andprovisioning, by the NaaS layer, a virtual network by configuring anunderlying physical network(s), to provide the network services for eachof the one or more network service requests, wherein the provisionedvirtual network is one of an overlay network or configured underlyingphysical network, wherein the overlay network is a tunnel networkoperating on top of the underlying physical network, wherein theunderlying physical network is provisioned by configuring underlyingphysical network elements; wherein the NaaS layer comprises a pluralityof interfaces including a north bound interface module, a south boundinterface module and an east west interface module for provisioningnetwork services in a cloud system; and wherein the NaaS layerfacilitates analysis and data exchange between instances of NaaS layerdeployed in one or more clouds and one or more public cloud interfacesin the east west interface module.
 2. The method of claim 1, wherein thesouth bound interface module includes a software defined network (SDN)and a non-SDN interface module on the south bound to communicate withcorresponding network control or a management system.
 3. The method ofclaim 2, wherein the south bound interface module interfaces with theSDN and non-SDN network control and management hardware and software. 4.The method of claim 1, wherein the north bound interface moduleinterfaces with the cloud system to provide network services forgraphical user interface (GUI) and one or more user applications.
 5. Themethod of claim 1, the NaaS layer further comprises a networkorchestration and intelligence module between the north bound interfacemodule and the south bound interface module, wherein the networkorchestration and intelligence module tracks a plurality of switches,inter-switch links and monitors elements of the underlying physicalnetwork.
 6. A system for provisioning network services in aheterogeneous cloud computing environment, the system comprising: atleast one processor; a memory communicatively coupled to the at leastone processor, wherein the memory includes a Network as a Service (NaaS)layer to: receive, by a cloud provisioning platform, one or more virtualmachine provisioning requests from a plurality of cloud administrators,wherein one or more virtual machine provisioning requests aredistributed to said cloud provisioning platform via a cloudorchestrator, assign of compute and storage resources to one or morevirtual machine provisioning requests and generate one or more networkservice requests for at least one of creation, update, or deletion of atleast one of virtual networks, subsets, ports, routers and interfaces bythe cloud provisioning platform, send the one or more network servicerequests to the NaaS layer by the cloud provisioning platform forprovisioning the network services; and provisioning, by the NaaS layer,a virtual network by configuring an underlying physical network(s), toprovide the network services for each of the one or more network servicerequests, wherein the provisioned virtual network is one of an overlaynetwork or configured underlying physical network, wherein the overlaynetwork is a tunnel network operating on top of the underlying physicalnetwork, wherein the underlying physical network is provisioned byconfiguring underlying physical network elements; wherein the NaaS layercomprises a plurality of interlaces including a north bound interfacemodule, a south bound interface module and an east west interface modulefor provisioning network services in a cloud system; and wherein theNaaS layer facilitates analysis and information exchange betweeninstances of network as a service layer deployed in one or more cloudsand public cloud interfaces in the east west interface module.
 7. Thesystem as claimed in claim 6, wherein the south bound interface moduleincludes a software defined network (SDN) and a non-SDN interface moduleon the south bound side of the NaaS layer (106) to communicate withcorresponding network control or a management system.
 8. The system asclaimed in claim 7, wherein the south bound interface module interfaceswith the SDN and non-SDN network control and management hardware andsoftware.
 9. The system as claimed in claim 6, wherein the north boundinterface module interfaces with the cloud system to provide networkservices for graphical user interface (GUI) and one or more userapplications.
 10. The system as claimed in claim 6, the NaaS layerfurther comprises a network orchestration and intelligence modulebetween the north bound interface module and the south bound interfacemodule, wherein the network orchestration and intelligence module tracksa plurality of switches, inter-switch links and monitors elements of thephysical network.
 11. A non-transitory computer readable mediumembodying a program executable in a computing device for provisioningnetwork services in a heterogeneous cloud computing environment, theprogram comprising: a program code for receiving, by a cloudprovisioning platform, one or more virtual machine provisioning requestsfrom a plurality of cloud administrators, wherein one or more virtualmachine provisioning requests are distributed to said cloud provisioningplatform via a cloud orchestrator; assigning of compute and storageresources to one or more virtual machine provisioning requests andgenerating one or more network service requests for at least one ofcreation, update, and deletion of at least one of virtual networks,subnets, ports, routers and interfaces by the cloud provisioningplatform; sending the one or more network service requests to a Networkas a Service (NaaS) layer by the cloud provisioning platform forprovisioning the network services; and provisioning, by the NaaS layer,a virtual network by configuring an underlying physical network(s), toprovide the network services for each of the one or more network servicerequests, wherein the provisioned virtual network is one of an overlaynetwork or configured underlying physical network, wherein the overlaynetwork is a tunnel network operating on top of the underlying physicalnetwork, wherein the underlying physical network is provisioned byconfiguring underlying physical network elements; wherein the NaaS layercomprises a plurality of interlaces including a north bound interfacemodule, a south bound interface module and an east west interface modulefor provisioning network services in a cloud system; and wherein theNaaS layer facilitates analysis and information exchange betweeninstances of network as a service layer deployed in one or more cloudsand public cloud interfaces in the east west interface module.